New Caledonia's SLN nickel company says it has transferred some employees and their families to Noumea after a night-time break-in at staff quarters.
The break-in occurred at SLN accommodation quarters in Kouaoua on the main island's east coast, when a group of men broke into their homes, setting one house on fire and burning a vehicle.
SLN said the affected residents - 10 adults and three children - were in shock after the raid, but none had been injured.
It said the safety of its staff was paramount and condemned the irresponsible behaviour of the perpetrators.
Police are investigating the attack which happened amid territory-wide restrictions on movements because of the Covid-19 outbreak.
Three people have been detained by police for questioning over the attack.
One of those being held is a minor.
SLN's Kouaoua site, which is on the east coast of the main island, has been a frequent target for arson attacks, in particular in 2018 when operations were interrupted for weeks.
The site provides ore which is shipped to the SLN smelter in Noumea.